The Auditory Environment at Early Intervention Groups for Young Children With Hearing Loss: Signal to Noise Ratio, Background Noise, and Reverberation.

Objectives: One important aspect in facilitating language access for children with hearing loss (HL) is the auditory environment. An optimal auditory environment is characterized by high signal to noise ratios (SNRs), low background noise levels, and low reverberation times. In this study, the authors describe the auditory environment of early intervention groups specifically equipped for young children with HL.

Design: Seven early intervention groups for children with HL were included in the study. A total of 26 young children (22 to 46 months) visiting those groups participated. Language Environmental Analysis recorders were used to record all sounds around a child during one group visit. The recordings were analyzed to estimate SNR levels and background noise levels during the intervention groups. The unoccupied noise levels and reverberation times were measured in the unoccupied room either directly before or after the group visit.

Results: The average SNR encountered by the children in the intervention groups was +13 dB SNR. The detected speech of the attending professionals achieved the +15 dB SNR recommended by the American Speech-Language-Hearing Association in approximately 42% of the time. The unoccupied noise levels were between 29 and 39 dBA, complying with acoustic norms for classroom environments (≤35 dBA, by ANSI/ASA 12.60-2010 Part 1) for six out of seven groups. Reverberation time was between 0.3 and 0.6 sec for all groups, which complies to the acoustic norms for classroom environments for children without HL (0.6 or 0.7 sec, depending on the room size), while only one group complied to the stricter norm for children with HL (0.3 sec).

Conclusions: The current findings show characteristics of the auditory environment of a setting that is specifically equipped and designed for groups of children with HL. Maintaining favorable SNRs seems to be the largest challenge to achieve within the constraints of an environment where young children gather, play, and learn. The results underscore the importance of staying attentive to keep spoken language accessible for children with HL in a group setting.